diff --git a/tests/testthat/helper.R b/tests/testthat/helper.R
new file mode 100644
index 0000000..ab4769e
--- /dev/null
+++ b/tests/testthat/helper.R
@@ -0,0 +1,10 @@
+test_path <- function(...) {
+  # testthat::test_path() returns incorrect value
+  # when in the context of devtools::test_coverage_active_file()
+  path <- file.path(...)
+  if (file.exists(path)) {
+    path
+  } else {
+    file.path("tests/testthat/", path)
+  }
+}